Hybridization in birds usually occurs between closely related species within the same genus. Intergeneric hybrids are of particular interest because they may be evidence of a close relationship between two genera. Originally described in the genus Mergus, the Hooded Merganser (L. cucullatus) was segregated in the genus Lophodytes in 1853, and the American Ornithologists’ Union has maintained it in that genus through all seven editions of its checklist. Delacour and Mayr (1945), however, lumped Lophodytes back into Mergus, and some authors, such as Johnsgard (1975, 1979), have followed this classification. In some respects the Hooded Merganser is intermediate between Bucephala and Mergus (Johnsgard 1961, Dugger et al. 1994). In his studies of waterfowl morphology and relationships, Livezey (1986, 1995, 1997) maintained the genus Lophodytes. He found the Hooded Merganser to represent an early branch of the mergansers, lying outside a cluster including the Common (M. merganser) and Red-breasted (M. serrator) mergansers and just above the branch leading to the genera Bucephala and Mergellus.